1. Field of the Invention
The invention relates to a tool which can be guided using a handle, having an operating element that is driven by an integrated power drive for the percussive, pounding or vibratory loading of a material to be worked, in particular a tamper, vibration plate or vibration roll for ground compaction or a hammer for breaking and/or drilling operations.
2. Discussion of the Related Art
In the case of devices of this type, the transmission of the shocks or vibrations to the handle is not only unpleasant but also damaging to health, for which reason the operating time is limited in accordance with the intensity of this action. Trouble is therefore taken to keep the oscillations of the handle as small as possible.
For this purpose, at present only a passive reduction in oscillations by spring-damper elements and inertial masses is known, which is accompanied by the disadvantage that a large reduction in oscillations is possible only via large spring travels, which, for its part, in turn impairs the ability of the tool to be guided, and that a high efficiency of the reduction in oscillations is achieved only at high frequency ratios .omega..sub.exciting /.omega..sub.inherent.
EP-A-206 981 discloses a hand-held tool having an oscillation generator to which there is fastened a handle that can be displaced to a limited extent between two stops, parallel to the main oscillation axis. The stop for the handle which is arranged in the advance direction of the hand-held tool is designed as an electromagnet, the electromagnet being operated with an essentially constant direct current and producing a force which counteracts the contact pressure applied by the operator. The force of the electromagnet is controllable, in order to enable adaptation to the conditions which depend on the orientation of the hand-held tool.